FLAC to ACC unlike original

[nol2ter]

Summary of the bug:
Sounds a little unnatural between 2:33 and 2:34 on Windows Media Player.
Unlike original, high notes are different.
eg) Lyrics -> eo-saeg-hae-seo

unnatural on Windows Media Player

How to reproduce:

ffmpeg version 3.4.2 Copyright (c) 2000-2018 the FFmpeg developers
  built with gcc 7.3.0 (GCC)
  configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-bzlib --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --enab
le-libsnappy --enable-libsoxr --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enabl
e-libspeex --enable-libxvid --enable-libmfx --enable-cuda --enable-cuvid --enable-d3d11va --enable-nvenc --enable-dxva2 --enable-avisynth
  libavutil      55. 78.100 / 55. 78.100
  libavcodec     57.107.100 / 57.107.100
  libavformat    57. 83.100 / 57. 83.100
  libavdevice    57. 10.100 / 57. 10.100
  libavfilter     6.107.100 /  6.107.100
  libswscale      4.  8.100 /  4.  8.100
  libswresample   2.  9.100 /  2.  9.100
  libpostproc    54.  7.100 / 54.  7.100
Input #0, flac, from '2m33s_sound_noise_original.flac':
  Metadata:
    COMMENT         : *deleted
  Duration: 00:03:39.55, start: 0.000000, bitrate: 941 kb/s
    Stream #0:0: Audio: flac, 44100 Hz, stereo, s16
Stream mapping:
  Stream #0:0 -> #0:0 (flac (native) -> aac (native))
Press [q] to stop, [?] for help
Output #0, ipod, to '2m33s_sound_noise.m4a':
  Metadata:
    encoder         : Lavf57.83.100
    Stream #0:0: Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp (16 bit), 320 kb/s
    Metadata:
      encoder         : Lavc57.107.100 aac
[ipod @ 0000000000516ce0] Starting second pass: moving the moov atom to the beginning of the file
size=    8528kB time=00:03:39.56 bitrate= 318.2kbits/s speed=  19x
video:0kB audio:8490kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.445842%
[aac @ 00000000004ebf80] Qavg: 13023.185

Patches should be submitted to the ffmpeg-devel mailing list and not this bug tracker.

[nol2ter]

Successfully uploaded.
​https://streams.videolan.org/ffmpeg/incoming/7062/

[nol2ter]

cmd : ffmpeg.exe -i 2m33s_sound_noise_original.flac -y -c:a aac -b:a 320k -ar 44100 -movflags +faststart -map 0:a -map_metadata -1 2m33s_sound_noise.m4a

[Carl Eugen Hoyos]

Please confirm that this issue is not reproducible with current FFmpeg git head, not even when using -aac_coder twoloop (which was the default for FFmpeg 3.4).